Suction-dredge



0. AND C. FRUHLING.

SUCTION DREDGE.

APPLICATION FILED M26, 1920.

Patented Oct. 11, 1921.v

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iizaelziwzsr 0. AND C. FRUHLING.

SUCTION DREDGEQ APPLICATION FILED JULY26, 1920.

Patented Oct. 11, 1921.

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UNITED STATES PATENT OFFICE.

OTTO FRI IHLING AND GURT FR'U'HLING, OF BRAUNSCI'UVEIG, GERMANY.

SUCTION-DREDGE.

Application filed July 26,

T 0 all whom it may concern:

Be it known that we, Or'ro FntjnLiNo and Cour Fnr'iHLiNo, subjects of the German Empire, and resident of Lowenwall 14, Braunschweig, Germany, have invented certain new and useful Improvements in Suction-Dredgers, of which the following is a specification, for which we have filed appli cations in Germany June 26, 1919, and in Great Britain July 9, 1920.

Suction dredgers may be sub-divided into two classes according to their method of operation, the first class being those which work on a movable floating tubular conduit or in pontoons while the second class operate with their own loading space.

In the first mentioned class, cutting tools of various constructions are employed to a large extent. The dredgers in such case generally work in front of anchors after the manner of bucket dredgers, being drawn to-and-fro over the whole breadth of the cut, on side chains, cutting transversely to the longitudinal axis. The pull due to the digging action of the cutting tools is in this case taken up by the anchors.

Dredgers of the second mentioned class are used principally in narrow ways where the employment of pontoons and floating tubular conduits is not possible owing to the lack of space. The throwing out of anchors and chains is also frequently impossible in such locations owing to the attendant interruption of the passage of ships and the dredgers therefore generally move freely in front of the screws. Cutting tools are comparatively seldom used in these dredgers and it has been found that the driving force of the ships propellers in the apparatus hitherto known, is not always suflicient in order to insure the necessary forward movement of the dredger.

It is the object of the present invention to overcome the foregoing disadvantages by the employment of disintegrating or loosening devices for the earth in the form of plows driven by motive power on the freely moving suction dredgers; the plows are employed for the reason that this form of cutting tool is most suitable for cutting the soil. The plow shaped devices hitherto used have been in the form of fixed members at the mouth of the suction tube or suction head in which case the foregoing disadvantages have arisen that the resistance could not be overcome merely by the propellers. The ro Specification of Letters Patent.

Patented Oct. 11, 1921.

1920. Serial No. 399,186.

tatably arranged plows driven by motive power eiiect the loosening of the soil without absorbing the power of the ships propellers so that the latter are utilized only for the propulsion of the vessel. If the plows are rotated in the corresponding direction, the earth resistance created by the plows may be utilized for the propulsion of the dredger.

The speed of revolution of the plows and the arrangement of a plurality of separate plows or plows of different construction en ables the dredging operation to be carried out according to the prevailing conditions.

On the drawings the constructional example of the invention is illustratechFigure 1 showing the after body of a freely moving suction dredger having a depending suction head and cutting device. Figs. 2, 3, and 4 are respectively vertical section, plan and front view of the suction head and cutters.

As illustrated the suction head A is in communication with the dredger pump through the suction tube B. Rotary plows l), E are mounted on a shaft C in front of the opening in the suction head A. The shaft 0 is rotated from the counter shaft I and the direction of rotation of the cutters E and the direction of motion of the dredger are indicated by the arrows in Fig. 1.

In the example illustrated in Fig. l four plows are illustrated, the outer plows being one-sided so as to press the earth inwardly while the inner plows E are double sided so as to press the earth to both sides thereof. The number and shape of the plows D and .ll may be varied according to the nature of the ground.

The rotating plows operate as indicated in Figs. 1 and 2 during the disintegration of the ground after the manner of a bucket wheel and act directly upon the ships propulsion. If desired plow shaped cutters may be employed on one or more shafts arranged either at an incline to or parallel to the ships axis. In order to create a propulsive force on the ship in such cases under all circumstances by the rotation of the cutters, the latter may be constructed as single sided plow shares and inclined in such a direction that during their operation a lateral force is created which acts to propel the ship forwardly.

Claims:

1. A self-propelled suction dredger comprising a suction head and rotary driven plow shares mounted in front of said'suction head and'adapted to rotate in such a direction as to assist the forward propulsion of the dredger.

2. A selfpropelled suction dredger ,as specified in claim 1 having lateral single sided plow shares and intermediate double sided plow shares.

3. A self-propelled suction dredger comprising a. rearwardly directed suction tube,

a hollow suction head on the lowerend of said tube, said head being provided with a icuwardlydirected inlet opening; a plurality of coaxially mounted plow shares carried by said head in front of said opening and mechanism for rotating said plow shares in such a direction as to assist the forward propulsion of the dredger.

OTTO FRUHLING.

OURT' FRUHLI G. 

